It's been a stressful day for AT&T, Apple, and Google, as the deadline looms for submitting comments to the Federal Communications Commission on their treatment of mobile VoIP. Although we're still waiting to hear Apple's side of things, AT&T issued a statement saying it had nothing to do with Apple's rejection of Google Voice app. Meanwhile Google has punctuated the tension ahead of the deadline, denying that it blocked a full-featured version of Skype on Android phones.

Here's a rundown of what's happened so far and what to expect next:

Google Voice:

In late July, Apple rejected the iPhone app for Google Voice, a call management utility that lets users forward calls, transcribe voicemail, send free text messages, and place cheap international calls. In addition the throwing out the official app, Apple removed third-party programs that channeled Google Voice independently. At the time AT&T denied that it lords over App Store decisions, though the carrier has crippled the functionality of at least one other program.

The Investigation:

Earlier this month, the FCC began an inquiry into the Google Voice fiasco. It's not an official investigation, but the FCC asked Apple and AT&T to explain why the app was rejected. Yesterday, a report from USA Today said Google was added to the hot seat, because of the limited capabilities of the Skype application for Android phones. Comments from all three companies are due today.

AT&T's Jim Cicconi, senior executive vice president for external and legislative affairs, issued a statement accompanying the company's response to the FCC stating AT&T had no role in Apple's rejection of the Google Voice app.

"AT&T was not asked about the matter by Apple at any time, nor did it offer any view one way or the other," Cicconi wrote.

Android and Skype:

In a post on the Google Public Policy Blog, Vice President of Mobile Platforms Andy Rubin wrote that Google "did not reject an application from Skype or from any other company that provides VoIP services. To suggest otherwise is false." While technical limitations once prevented a full-featured Skype app, Rubin effectively blamed the current lack of true VoIP apps on developers, saying no one has submitted one yet. Rubin did acknowledge that wireless carriers can filter applications that violate their terms of service, though T-Mobile has denied that it weighed in on Skype.

The Key Issues:

Because this isn't an official investigation, it's not clear what the FCC is ultimately trying to determine, but in general the government wants to know why certain VoIP apps are being rejected and others are not. This goes to the issue of net neutrality, and whether handset makers and wireless carriers are stifling apps that could amount to competition. Also, this inquiry fits into the FCC's broader look at exclusivity deals between phone makers and wireless carriers.

What Happens Now?

In short, the good stuff. This whole fiasco has been pretty shady from the start, from the contradiction between AT&T's actions and public statements to Google's blame game over Skype for Android. I expect all three companies to wriggle and spin their comments, but in the end we should get a more thorough explanation of the situation than ever before. Ladies and gentlemen, your tax dollars at work.

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